The chuck is essentially a type of clamp, and threads onto the motor’s shaft and is what holds the drill bit. A chuck can keyed or keyless or an SDS chuck (used on hammer drills only). Keyed chucks aren’t as user-friendly but hold the bit in place tighter so high torque won’t loosen it; keyless chucks don’t hold the bit as tightly but are more convenient (especially for home use) as it doesn’t require a key to loosen/tighten.
This item fits the following models:
15-pc Thunderbolt Black Oxide Drill Bit Set
1/4" x 50 Ft Noodle Air Hose with Coupler and Plug